The Bodhisatta was once a dice player. One day he learned that one of the men he played with was a cheat, putting one of the dice in his mouth to pretend it was lost so games would have to end at the opportune time for him. The next time they played the Bodhisatta covered his dice in a dried poison. As soon as he started to lose, the cheat put a die in his mouth. As the Bodhisatta called him out for his scam and told him about the poison, the cheat began to grow faint and doubled over in pain. The Bodhisatta then gave him a medicine to make him vomit, saving his life, and told him not to cheat again.
In the Lifetime of the Buddha
The Buddha found that most of his disciples did not take care of the robes and other requisites (food, lodging, and medicine) provided to them, and doing this was bad enough to result in re-birth in hell or the animal world. So the Buddha made specific rules about the proper use of the four requisites and told them this story so they understood that using things thoughtlessly is like taking poison.
The Buddha did not identify any earlier births other than his own.